222 Fertilisation and Hybridisation 



hairy or thorny. The crossing of a common evening- 

 primrose with a large-flowered species results in a flower 

 of the size of the former. But, if there are two or more 

 points of difference they may be transmitted to the chil- 

 dren partly by the one parent and partly by the other, and 

 it is thereby possible in practice to combine the good char- 

 acters of two varieties into a single race. Thus has Rim- 

 pau created a series of hybrid-races of wheat, and Lemoine 

 has produced his large-blooming sword-lilies, able to with- 

 stand the winter, and thus have originated, in agriculture 

 and horticulture, the countless hybrids, in which the fa- 

 vorable characteristics of various varieties are combined 

 with more or less diversity. Combined, or as we usually 

 say, mixed ; though this is an expression which makes us 

 only too easily lose sight of the independence of the in- 

 dividual factors in the mixture. 



This independence is frequently difficult to demon- 

 strate in the mixtures, that is, in the characteristics of the 

 hybrids. Our means of differentiation only too frequently 

 prove insufficient. In the clear cases, however, it appears 

 very distinctly, and the greater the number of hybrids that 

 are studied accurately and thoroughly, the more generally 

 is the validity of the principle established. 



If, for example, we find combined in a wheat-hybrid, 

 the loose ear of the mother-plant, with the lack of awns 

 in the father, the share of each appears simple and clear. 

 In the mixture of the characteristics these two are so far 

 apart, that they are always easily recognized. How are 

 such characters united in the hybrid ? Are they fused into 

 one whole, or do they simply lie loosely side by side ? 



The splittings, which occur regularly in many hybrids, 

 when propagated by seed, and also, in the case of a few, in 

 vegetative propagation, give us an answer to this question. 



